1. Field of the Invention
This invention relates generally to wireless services. More particularly, it relates to E911 wireless services.
2. Background of the Related Art
The FCC has mandated that all wireless telephones must be able to dial 9-1-1, even if other service is denied. This includes uninitialized phones (i.e., cellular phones that have not yet been activated by the wireless carrier). Uninitialized phones have no assigned phone number and are virtually untraceable. Because of this, they have become a popular way for mischief-makers to place hundreds or thousands of harassment calls to Public Safety Answering Points (PSAPs), thereby compromising the ability of the PSAPs to respond to real emergencies.
FIG. 3 shows conventional elements relating to routing of an E911 call from a cell phone.
In particular, as shown in FIG. 3, a conventional wireless carrier's mobile switching center (MSC) 502 contacts a Mobile Positioning Center (MPC) 504 to ascertain proper routing of an E911 call. The MPC 504 responds with routing information and the MSC 502 then routes the call to the correct PSAP 208. The MPC 504 stores the caller's call-back number and location in a dynamic database and relays that information to the PSAP 208 at the appropriate time.
Currently, uninitialized phones are identified only with a nonfunctional, simulated “callback” number that consists of a portion of the phone's electronic serial number (ESN). The FCC has authorized wireless carriers to terminate service to these phones if the PSAP identifies the phone as a harrasser. Some MSCs are capable of blocking single ESNs, while others are less flexible and must block all uninitialized phones. The effort to block these calls at the MSC 502 is time consuming and troublesome.
Thus, disadvantages of the current solutions include: (1) It requires time consuming manual intervention to block identified calls; (2) Once a call is blocked, it remains blocked until a technician manually restores service; and (3) Some wireless switches cannot block individual telephones.
Moreover, once blocked, the subsequent legitimate user of the phone is not advised that the phone has been blocked.
There is a need for improved technology for blocking E911 calls from a non-initialized wireless telephone deemed to have previously been used to make a harassing or illegitimate call to 9-1-1.